This is an application for a 2nd NIMH K02 award. The applicant's research has dealt with the psychobiology of stress in young children, emphasizing activity of the hypothalamic-pituitary-adrenocortical (HPA) system an adequate understanding of the psychobiology of stress in childhood, however, requires integration of our rich understanding of psychosocial processes in human development, with our emerging understanding of multiple stress-sensitive physiological systems. Much of the first K02 period has been spend developing collaborative relations and beginning expertise that has allowed me to obtain funding for a 5-year period to test an integrative (temperament-coping resources-stress) psychobiologic model of stress in childhood. According to this model, a "stress reactive" temperament (the biological components of which are assessed through baseline EEG asymmetry, vagal tone, basal HPA activity, and positive late components of the ERP) influences the child's likelihood of perceiving events as potentially threatening. However, activation of physiological stress reactions (cardiac, HPA, and immune) are presumed to follow from expectations that the threat will be realized. Mediating these reactions are the coping resources (person and situation factors) available to the child. The proposed studies are designed to integrate 3 major literatures: (1) the physiology of infant/child temperament, (2) socioemotional development, including attachment research, and (3) psychobiologic studies of infant/child stress. This Career Plan emphasizes the need to extend this research to the study of child health (e.g. stress-immune functioning-infectious disease) issues in pediatric research (i.e., pain regulation, colic), high risk populations (i.e., maltreated children, early deprivation(, and to include other systems important in the regulation of stress (i.e., sleep as a process variable). Preliminary work, collaborative relations (with T. Boyce, R. Barr, R. Dahl, S. Suomi, M. Carlson, D. Cicchetti), and pilot data are described to support need for release time to enhance training and research into these related areas. The Institute of Child Development and the University of Minnesota provide rich resources for the candidate's career development. The institute is fully committed to this award as evidenced in the last K02 period. The candidate's would continue to be able to commit 80 percent time to research, with a minimal teaching load and additional support for travel and the development of collaborations within and without the university.